1. Technical Field
This disclosure relates generally to a thrust reverser for an aircraft propulsion system and, more particularly, to methods of forming cascades for a thrust reverser.
2. Background Information
A typical aircraft propulsion system such as a turbofan turbine engine may include a thrust reverser for redirecting bypass air forward to generate reverse thrust. Several types of thrust reversers are known in the art. Many of these thrust reversers include a cascade array, which provides a series of aerodynamic vanes for redirecting the bypass air in a desired forward direction during reverse thrust operation.
Several methods have been used to manufacture cascades. Some exemplary methods include casting the cascade, machining the cascade, and fastening, welding or brazing cascade components such as vanes and strongback rails together. The foregoing methods, however, are most relevant to metallic cascades. Today, composite cascades are favored for their weight savings versus metallic cascades.
The principal method in use today to manufacture composite cascades utilizes a closed-die or autoclave molding process. Carbon fiber fabric is laid up in a mold around flexible mandrels that define the open passageways of the cascade. The layup process is generally done by hand and is very labor intensive. The die is closed and compressed to apply consolidation pressure to the fabric layers or the tooling is vacuum bagged and cured in the autoclave under pressure. After molding, the flexible mandrels must be extracted. The process is very expensive and difficult.
There is a need in the art for an improved method for manufacturing a fiber-reinforced composite thrust reverser cascade.